Hidden Danger Lurks in Millions of Old Oil and Gas Wells

Old, abandon oil and gas wells, most of them unmarked, pose a significant environmental threat, according to a new report from ProPublica. In Ohio, Kentucky, Michigan and several other states, there have been documented instances where such abandoned wells became pathways for oil, gas and other pollution to contaminate water supplies.

According to the ProPublica investigation, which was conducted in cooperation with the Pittsburgh Post-Gazette, energy companies have drilled as many as 12 million holes across the United States in search of oil and gas.

For decades, government reports have warned that abandoned wells pose a pollution hazard. The most recent effort to count the nation’s unplugged wells was a survey published in 2008 by the Interstate Oil and Gas Compact Commission. It counted nearly 60,000 that need to be plugged, but most experts agree there are likely millions. According to ProPublica, in Pennsylvania alone, there are estimated to be more than 180,000 such wells. If these old wells were plugged at all, it was probably done with rocks or old stumps.

Some regulators fear that the number of abandoned wells will grow when the current drilling boom runs its course. While most states now require drillers to post bonds before they begin work on a new well, ProPublica said it is often more economical for a company to forfeit its bond rather than plug its wells. In Pennsylvania, for instance, hundreds of wells can be covered with a single $25,000 bond.

Old abandoned wells have been causing problems for communities throughout the U.S. ProPublica said. Below are some of the cases detailed by its report:

â€¢ In 1989, the Government Accounting Office found nine cases where abandoned wells had contaminated groundwater, including one Kentucky case that rendered the water for more than 80 households undrinkable.

â€¢ Ohio’s Department of Natural Resources found 41 cases where abandoned wells contaminated private water supplies from 1983 through 2007.

â€¢ The Environmental Protection Agency’s (EPA) 2004 study of hydraulic fracturing said that old, abandon wells were at least partially responsible for gas migration into water wells and buildings in Colorado’s San Juan Basin.

â€¢ A 2008 blast in Pennsylvania was sparked when someone lit a candle in a home bathroom, unaware that gas from an abandoned well nearby had leaked into the septic system. The resident was killed.

â€¢ Just this past February, methane from an old well made its way into the basement of a house in West Mifflin, Pennsylvania, triggering a small explosion. Two families were evacuated and have not yet returned home.

â€¢ In an internal briefing last year EPA scientists raised concern that fracking near Pennsylvania’s many abandoned wells could threaten groundwater, saying the old wells “may present a risk unique to the hydrofrac process.”